add "gui display"

This adds the "gui display" command.
It arranges to re-evaluate a gdb command at each change
and display the results in a window.

gui/commands.py

@@ -20,6 +20,7 @@ import gui.logwindow
 import gui.toplevel
 import gui.dprintf
 import gui.events
+import gui.display
 import re
 from gui.startup import in_gtk_thread
 
@@ -126,6 +127,24 @@ class GuiDprintfCommand(GuiPrintBase):
         spec = arg[0 : -len(arg)]
         DPrintfBreakpoint(spec, window, arg)
 
+class GuiDisplayCommand(gdb.Command):
+    """FIXME"""
+
+    def __init__(self):
+        super(GuiDisplayCommand, self).__init__('gui display',
+                                                gdb.COMMAND_SUPPORT)
+
+    def invoke(self, arg, from_tty):
+        self.dont_repeat()
+        # FIXME: perhaps Toplevel should be calling startup_gtk
+        gui.startup.start_gtk()
+        gui.display.DisplayWindow(arg)
+
+    def complete(self, text, word):
+        # FIXME, see
+        # https://sourceware.org/bugzilla/show_bug.cgi?id=13077
+        return None
+
 class InfoWindowsCommand(gdb.Command):
     def __init__(self):
         super(InfoWindowsCommand, self).__init__('info windows',
@@ -153,6 +172,7 @@ GuiLogWindowCommand()
 GuiPrintCommand()
 GuiOutputCommand()
 GuiPrintfCommand()
+GuiDisplayCommand()
 InfoWindowsCommand()
 DeleteWindowsCommand()
 

gui/display.py

@@ -0,0 +1,80 @@
+# Copyright (C) 2013 Tom Tromey <tom@tromey.com>
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Log window.
+
+import gdb
+import gui.toplevel
+import gui.startup
+from gi.repository import Gtk
+import functools
+from gui.startup import in_gdb_thread, in_gtk_thread
+import gui.events
+
+# FIXME: TO DO:
+# * highlight the changes
+
+class DisplayWindow(gui.toplevel.Toplevel):
+    def __init__(self, command):
+        super(DisplayWindow, self).__init__()
+        self.command = command
+        gui.startup.send_to_gtk(self._initialize)
+        self._connect_events()
+        # Display the data now.
+        self._on_event()
+
+    @in_gdb_thread
+    def _connect_events(self):
+        # FIXME - we need an event for "selected frame changed".
+        # ... and thread-changed
+        # really just pre-prompt would be good enough
+        gdb.events.stop.connect(self._on_event)
+        gui.events.frame_changed.connect(self._on_event)
+
+    @in_gdb_thread
+    def _disconnect_events(self):
+        gdb.events.stop.disconnect(self.on_event)
+        gui.event.frame_changed.disconnect(self.on_event)
+
+    @in_gdb_thread
+    def _on_event(self, *args):
+        try:
+            text = gdb.execute(self.command, to_string = True)
+        except gdb.error as what:
+            text = str(what)
+        gui.startup.send_to_gtk(lambda: self._update(text))
+
+    @in_gtk_thread
+    def _initialize(self):
+        builder = gui.startup.create_builder('logwindow.xml')
+        builder.connect_signals(self)
+
+        self.window = builder.get_object('logwindow')
+        self.view = builder.get_object('textview')
+        self.buffer = builder.get_object('buffer')
+
+        self.window.set_title('GDB "%s" @%d' % (self.command, self.number))
+        self.window.show()
+
+    @in_gtk_thread
+    def remove(self, window):
+        self.windows.remove(window)
+        if len(self.windows) == 0:
+            gdb.post_event(self._disconnect_events)
+
+    def _update(self, text):
+        self.buffer.delete(self.buffer.get_start_iter(),
+                           self.buffer.get_end_iter())
+        self.buffer.insert_at_cursor(text)